Concrete sawing machine for making parallel grooves



Oct. 7, 1958 w. H. LEWIS 2,855,139

CONCRETE SAWING MACHINE FOR MAKING PARALLEL GROOVES Original Filed Dec. 23, 1950' INVENTOR. MLL/AMfiI/RsrLEW/J A TTOR/VEYJ United States Patent Ofiice 2,855,189 Patented Oct. 7, 1958 CONCRETE SAWING MACHINE FOR MAKING PARALLEL GROOVES William H. Lewis, Arcadia, Calif., assignor to Cutcrete Manufacturing Company, El Monte, Calif, 21 corporation. of. California Original application December 23', 1950, Serial No. 202,445. Divided; and this, application March 15, 1956, Serial No. 571,705

3 .Claims. (Cl. 262-20) This application is a division of application Serial No. 202,445, filed by me December 23, 1950, and now abandoned.

This invention relates to road making machinery, and more especially to a concrete cutting saw for making trenches in roadways.

An object of the invention is to provide novel improvements in the construction of a saw for cutting concrete slabs such as roads, sidewalks, floors, and the like.

Other objects and advantages will appear and be brought out more fully in the following specification, reference being had to the accompanying drawings wherein:

Figure l is a side elevational view showing a preferred embodiment of the present invention, and

Figure 2 is a top plan view of said embodiment.

Referring more particularly to the drawing, I show a concrete cutting machine having a main frame or chassis 11, supported by front wheel assembly (not shown) and a rear wheel assembly having a pair of rear wheels 15. A base 16 is mounted on frame 11 and supports an internal combustion engine or other motor 20.

A plate 21 is secured at an angle to the rear end of frame 11 and has bearing brackets for a shaft 23a on which is a pulley 24 driven by a belt 25 from a pulley 26 on the drive shaft of engine or motor 20.

A saw blade 44 is keyed to one end of the shaft 23a. An auxiliary saw frame 81 comprises a pair of L-section rail or plate members 82 having bearing connections 83 to shaft 23a and a pair of similar plates 84 having slot and bolt connections 85.and 86 with rails 82, and a transverse plate 87 connecting one end of rails 84. Plate 87 mounts bearings 88 for a saw blade shaft 90 having a saw blade 91 at one end and a pulley 92 at the other end, to be driven by belt 93 from a pulley 94 on saw shaft 23a. An arcuate plate 95 having an open end slot 96 is suitably mounted on frame 11. A link assembly 97 connected to plate 87 engages plate 95 and comprises a tube member 98 which receives one end of a rod 99 having a pivot connection 100 to plate 87.

' A stop collar 101 is adjustably positioned on rod 99 and seats one end of a compression spring 102, the other end of which engages one end of tube 98. Rod 99 has a radially extending pin 103 in slot 104 in tube 98. A handle 105 has a shank connected to tube 98 and is adapted to pass through slot 96, this slot being sufiiciently wide to admit rod 99 when in adjusted position. By this construction, when saw blade 91 is in operative position, shaft 90 will be urged downwardly by the pressure of spring 87, bearing against tube 98 which is in engagement with the outer arcuate face of plate 95. When it is desired to move saw blade 91 from operative position, this may be accomplished by swinging frame 81 clockwise and lifting handle member 105 out of slot 96, and turns of spring 102 with rod 99 extending through the slot, as shown in the dotted position of Figure 1.

In the operation of the aforedescribed device, two parallel cuts can be made using both blades 44 and 91.

Blade 44 may be positioned on either end of shaft 23a, if desired, as indicated in dotted outline in Figure 1. It is important to observe that with the aforedescribed construction, the blades 44 and 91 will not bind within their grooves formed in the pavement even when one blade is lowered or raised relative to the other. This is true because each blade is mounted on a separate shaft which may undergo relative vertical movement independently of the other. Accordingly, should one of the two blades'rise relative to the other blade it may do so independently of the other blade and without causing the other blade to become canted relative to its groove. If such vertical canting were to occur, the blade would bind within the sides of its groove. If both of the blades were to be keyed to a single shaft, 2. change in elevation of either would cause one or both of them to become wedged in their respective groove. This could easily cause serious blade damage.

From the foregoing description it should be clear that my invention fulfills the above enumerated objects and has novel advantages, and it will be further understood that the foregoing is illustrative rather than restrictive of the invention, and that changes and modifications may be made without departing from the spirit and scope of the sub-joined claims.

I claim:

1. A concrete sawing machine for forming a trench in a concrete surface, comprising: a chassis having a main frame; front and rear wheels on said chassis supporting it for longitudinal movement across said concrete surface; a transverse shaft rotatably journaled by the rear portion of said main frame; an auxiliary frame pivotally supported by said shaft and extending rearwardly from the rear portion of said main frame; a second transverse shaft supported by the rear portion of said auxiliary frame; first and second cutter discs keyed respectively to said first-mentioned shaft and said auxiliary shaft, said discs being transversely spaced whereby they may cut parallel grooves in said concrete surface as said chassis is moved thereacross, said shafts being free to undergo relative vertical movement independently of one another whereby one of said discs may undergo vertical movement relative to the other without causing the latter to become canted; resilient means interposed between said chassis and said auxiliary frame constantly biasing the rear portion of said auxiliary frame downwardly; and power-operated means on said chassis for rotating said cutter discs.

2. A concrete sawing machine for forming a trench in a concrete surface, comprising: a chassis having a main frame; front and rear wheels on said chassis supporting it for longitudinal movement across said concrete surface; a transverse shaft rotatably journaled by the rear portion of said main frame; an auxiliary frame pivotally supported by said shaft and extending rearwardly from the rear portion of said main frame; an auxiliary transverse shaft supported by the rear portion of said auxiliary frame; first and second cutter discs keyed respectively to said first-mentioned shaft and said auxiliary shaft, said discs being transversely spaced whereby they may cut parallel grooves in said concrete surface as said chassis is moved thereacross, said shafts being free to undergo relative vertical movement independently of one another whereby one of said discs may undergo vertical movement relative to the other without causing the latter to become canted; resilient means interposed between said chassis and said auxiliary frame constantly biasing the rear portion of said auxiliary frame downwardly; power-operated means on said chassis; belt means drivingly interconnecting said first-mentioned shaft and said auxiliary shaft; and second belt means drivingly interconnecting said first-mentioned shaft and said power-operated means.

3 A concrete sawing machine for forming a trench in a concrete surface, comprising: a chassis having a main frame; a main transverse shaft on said main frame; an auxiliary transverse shaft supported by said main frame so as to be independently vertically movable relative thereto; spring means interposed between said main frame and said auxiliary shaft constantly biasing said auxiliary shaft downwardly relative to said main frame; front and rear wheels on said chassis supporting it for longitudinal movement across said concrete surface; first and second cutter discs, said main and auxiliary shafts respectively rotatably supporting said first and second cutter discs with said cutter discs being transversely spaced whereby they may cut parallel grooves in said concrete surface as said chassis is moved thereacross and with said shafts References Cited in the file of this patent UNITED STATES PATENTS 1,102,904 Gehrke July 7, 1914 1,331,367 Petermann Feb. 17, 1920 2,400,906 Beck May 28, 1946 FOREIGN PATENTS 551,996 Great Britain Mar. 18, 1943 

